The yearning for the common good comes from the refusal to accept that perhaps Americans have very little in common apart from the elements of a sometimes successful civil religion based around a sentimental, indeed sometimes teary-eyed, attachment to the constitution and a belief in the quasi-divine wisdom of the founding fathers.

We must believe, but we can't believe. Perhaps this is the tragedy that some of us see in Obama: a change we can believe in and the crushing realisation that nothing will change.

In relation to the question of hope, I think the only hope we have is hope against hope. We hope for a better world. But of course we can do better than just hope.

Shore up the mean with reverence and terror. But never banish terror from the gates of the state. The stronger the fear, the stronger the reverence for the just, the stronger your country's wall and the city's safety.

I am opposing it with an idea of the history of philosophy as a history of philosophers, that is, a history of mortal, fragile and limited creatures like you and I. I am against the idea of clean, clearly distinct epochs in the history of philosophy or indeed in anything else. I think that history is always messy, contingent, plural and material. I am against the constant revenge of idealism in how we think about history.

The other side of my work is political disappointment - the realization that we are living in an unjust world. "Blood is being spilled in the merriest way, as if it was champagne," Dostoevsky says. That raises the problem of justice, what it might mean in an unjust world and whether there can be an ethics and a political practice that would be able to face and face down the injustice of the present. How might we begin to think about that?

The only answer to the question of the meaning of life has to begin from the fact of our human finitude, of our vulnerability and our fallibility.